KITTI[1]}: The point clouds of KITTI dataset was scanned by a Velodyne HDL-64E LiDAR. Among the datasets, sequence 08 has reverse-only loops, sequence 02 has different direction loops, and sequence 00, 05, 06, 07 have same loops. We chose six sequences: 00, 02, 05, 06, 07, 08.
